package com.itheima.reggie.filter;


import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.log4j.Log4j;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 过滤器
 * @author jay
 */
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //1、获取本次请求的URI   /backend/index.html
        String requestURI = request.getRequestURI();
        log.info("拦截到请求{}",requestURI);
        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };
        //2、判断本次请求是否需要处理,如果不需要处理，则直接放行
        boolean check = check(urls, requestURI);
        if (check) {
            log.info("本次请求{}无需处理",requestURI);
            filterChain.doFilter(request, response); //放行
            return;
        }
        //3-1、判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employee") != null) {
            log.info("用户已登录，id为{}",request.getSession().getAttribute("employee"));
            //调用BaseContext来设置当前登录用户的id
            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);
            filterChain.doFilter(request, response); //放行
            return;
        }
        //3-2、判断移动端登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("user") != null) {
            log.info("用户已登录，id为{}",request.getSession().getAttribute("user"));
            //调用BaseContext来设置当前登录用户的id
            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId); //ThreadLocal 绑定用户id

            filterChain.doFilter(request, response); //放行
            return;
        }
        //4、如果未登录则返回未登录结果,通过输出流向客户端页面响应数据
        log.info("用户未登录");
        String jsonString = JSON.toJSONString(R.error("NOTLOGIN"));
        response.getWriter().write(jsonString);
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
